In the manufacture of a semiconductor light emitting device such as a laser, the light emitting element is soldered or bonded to a mount. The mount is typically a good thermal conductor, such as copper, which heatsinks the light emitting element to alleviate any damage that could result from the heat buildup which is typical during operation.
In mounting a laser diode it is critical to accurately align the lasing facet of the diode with the edge of the mount. If the laser diode extends beyond the edge of the mount, the hottest part of the laser, the lasing facet, will not be adequately cooled by the heatsink. However, if the laser diode is mounted back from the edge of the mount, an interference effect caused by reflection of some of the light by the mount surface scatters the rest of the light beam.
More recent applications of the semiconductor laser require the use of both front and back lasing facets. Therefore, based on the stringent requirements for aligning the edge of the diode with the edge of the mount, it becomes apparent that the mount dimensions must correspond to the diode dimensions. Machining mounts to precise sizes is not a problem. However, in cleaving or dicing a processed semiconductor wafer into diodes, it can be very difficult to get exact sizes of the diodes. In high volume production of semiconductor laser devices the devices do indeed vary in size and it is not practical to custom-make mounts for all possible diode sizes.
It would be desirable therefore to have a mount which could simplify a mass production mounting process in which both facets of variably sized light emitting elements must be aligned with the edges of a mount.